简而言之，元数据就是关于数据的数据。图书馆目录卡就是元数据的一个例子。这些卡片包含一些关于图书的数据。例如，卡片上可以有类别、代码、书名、作者和书的简介。有了这张卡，你就可以找到一本书在图书馆的确切位置。但首先，元数据必须有一种产生的方式。
元数据、互联网和数字服务
元数据、互联网和数字服务In this digital era, the internet and many digital services rely on metadata for them to function properly. For instance, the internet uses packets which carry information from one destination to another. the packets contain a header which is full of metadata. This metadata informs the internet services and nodes where the respective information should be directed. Below are some ways in which metadata makes other digital services we use daily to work as intended;
在互联网上冲浪--如果没有元数据，我们在互联网上搜索的网页就找不到。网页必须携带一些元数据，包括标题、描述、关键词等。搜索引擎利用这些元数据来获取网页。
Social media and networking – our social media accounts almost have every detail of information about us. if you have been keen, you might have realized you have used Facebook, Twitter or Google to log into other third-party apps/sites. Usually, when this happens, you give access to basic information such as date of birth, your friend list and even permission to post on your behalf. In simple terms, these third-party apps are requesting access to your metadata in which they use to identify you when you log in in future.
Digital entertainment catalogues – have you ever wondered how after listening to a few songs in online streaming services, you get suggestions that match your preference? Or after watching some few movies in Netflix you get a new row of movies you might like? it’s all because of the metadata sometimes scrapped from items you had selected earlier.
通常，我们使用的所有数字设备都有元数据，从音乐到电子邮件，甚至电话。
元数据与您的隐私
As much as metadata is useful, it’s also a threat to your privacy. As seen above, most metadata contain our personal information such as what third-parties request off social media sites. Also, cookies and other trackers are constantly collecting metadata and sending them to data-hungry startups which in turn have neatly compiled our preferences and browsing behaviours. This metadata becomes harmful when it is sold to other third parties, that’s when privacy risks and threats arise. Below are some entities that can compromise our privacy by having access to our metadata;
网络犯罪分子
cybercriminals can have access to our metadata from a third-party organization and even from cookies and trackers. With this metadata, they can propagate further attacks such as blackmail, vishing, and smishing attacks and to some extent identity fraud.
政府机构和机关
Intelligence agencies may gather metadata from ISPs and other organization which they then use to monitor an individual.
营销人员
Most organizations use ads as their main source of income. This can be done directly and indirectly. For instance, you might have noticed you are getting a lot of ads on your social media sites. Most of the ads are not social media related but they are about a product and chances are 80% you might be interested in the product. All this is possible via metadata. For instance, your Facebook interest and likes can be used to suggests pages and target you with ads.
如何确保安全，使用 VPN
由于元数据是数字世界的主宰，因此很难避免分享你的信息，你现在甚至可能正在产生更多的元数据。你唯一能做的就是将风险降到最低，而使用VPN 就能做到这一点。
